Penrith City Council completed a broad-scale overland flow flood study (”Overview Study”) in October 2006 (Cardno Lawson Treloar, 2006) in order to prioritise future detailed overland flow flood studies for all catchments within the Penrith Local Government Area (LGA) in according with the NSW Government’s Floodplain Development Manual, 2005.
Penrith CBD Detailed Overland Flow Flood Study is an outcome of that process. Compared with previous “Overview Study”, the key features associated with Penrith CBD Detailed Overland Flow Flood Study are:
- A fine 1m grid was applied within the study area in order to identify the overland flow paths in detail; and
- Detailed 1D components were incorporated within the 2D grids, including pits, pipes, channels, and other hydraulic control structures.
The primary objective of the study is to define flood behaviour for the study area under existing conditions that the features of overland flowpaths and the drainage system. The study provides information on flood
extents, flood levels, flows, depths, and flood velocities for a full range of design storm events, including 1 year, 2 year, 5 year, 10 year, 20 year, 50 year, 100 year, and 200 year ARI storm events together with the Probable Maximum Flood (PMF) event. This study also defines provisional hazards, hydraulic categories and quantifies the flood damages for the study area. The results of the study may form the basis for subsequent Floodplain Risk Management and Plan for the study area.
